Atypical presentation of cystic fibrosis: Obese adolescent with hypertension and pseudo-Bartter’s syndrome

Abstract

Introduction. Infants with cystic fibrosis may fail to thrive despite recommended caloric intake because of electrolyte disurbances caused by salt depletion resulting in hypochloremic metabolic alkalosis or pseudo-Bartter's syndrome. In most patients reported symptoms began in infancy, but it may be an initial presentation of disease in a previously healthy adolescent. Case report. A 15-year-old boy was admitted for evaluation of recurrent episodes of malaise associated with dehydration and acute renal insufficiency. Laboratory analysis showed hypochloremic metabolic alkalosis with hyponatremia and hypokalemia. On admission the boy was obese, with body weight of 95.5 kg (> P97), height 174 cm (> P75), and body mass index of 31.2 kg/m2 (> P95). Physical examination was inconclusive. Blood pressure holter monitoring proved significant systolic hypertension. Routine urinalysis, protein and electrolyte levels in urine were normal. Plasma renin and aldosteron were normal. Sweat chloride concentration was 63 mmol/L. Genetic testing confirmed the diagnosis of cystic fibrosis. Conclusion. To our knowledge, this is the first reported case of atypical presentation of cystic fibrosis in an adolescent presented with pseudo-Bartter's syndrome and signs of obesity and hypertension. We suggest that every patient with hypochloremic metabolic alkalosis should be evaluated for cystic fibrosis.Uvod. Odojcad obolela od cisticne fibroze mogu zaostajati u tezini uprkos dobrom kalorijskom unosu, zbog elektrolitnih poremecaja prouzrokovanih gubitkom soli, sto dovodi do hipohloremijske metabolicke alkaloze ili pseudo-Barterovog sindroma. Simptomi najcesce pocinju u uzrastu odojceta, ali mogu biti inicijalna manifestacija oboljenja kod predhodno zdravih adolescenata. Prikaz bolesnika. Decak uzrasta 15 godina primljen je zbog ispitivanja ponavljanih epizoda malaksalosti, udruzenih sa dehidracijom i akutnom bubreznom insuficijencijom. Laboratorijskim analizama utvrdjeno je postojanje hipohloremijske metabolicke alkaloze sa hiponatrijemijom i hipokalijemijom. Decak je bio gojazan sa telesnom masom 95,9 kg (> P97), telesnom visinom 174 cm (> P75) i indeksom telesne mase 31,2 kg/m2 (> P95). Fizikalni nalaz bio je uredan. Holter monitoringom arterijskog pritiska utvrdjena je znacajna sistolna hipertenzija. Rutinski pregled urina, nivo proteina i elektrolita u urinu, bili su normalni, kao i koncentracija renina i aldosterona u serumu. Vrednost hlorida u znoju iznosila je 63 mmol/L. Genetskim probama potvrdjena je dijagnoza cisticne fibroze. Zakljucak. Prema saznanjima autora, ovo je prvi prikaz adolescenta sa atipicnom prezetacijom citicne fibroze, kod koga se bolest ispoljila kao pseudo-Barterov sindrom, gojaznost i hipertenzija. Kod svakog bolesnika kome se utvrdi hipohloremijska metabolicka alkaloza treba razmotriti postojanje cisticne fibroze.